Conventionally, there has been known an electrolyte capacitor where an insulating material is disposed between a bottom surface portion of a housing and a capacitor element (see patent literature 1, for example).
FIG. 15A and FIG. 15B are views for explaining a conventional electrolyte capacitor 900. FIG. 15A is a cross-sectional view of the electrolyte capacitor 900, and FIG. 15B is an exploded perspective view of a capacitor element 920. In FIG. 15, symbols 950, 952 indicate lead lines.
As shown in FIG. 15, the conventional electrolyte capacitor 900 includes: a metal-made housing 910 having a bottom surface portion 912, a side surface portion 914 raised from the bottom surface portion 912 and an opening portion 916 formed on an end portion of the side wall portion 914; a capacitor element 920 housed in the inside of the housing 910 and formed by winding an anode foil 922 and a cathode foil 924 in an overlapping manner with a separator 926 interposed therebetween and by filling an electrolyte solution (not shown in the drawing) in between the anode foil 922 and the cathode foil 924; and a sealing member 930 sealing the opening portion 916 of the housing 910 in a state where the capacitor element 920 is housed in the inside of the housing 910, wherein an insulating material 940 is disposed between the bottom surface portion 912 of the housing 910 and the capacitor element 920.
In the conventional electrolyte capacitor 900, an oxide film is formed on a surface (including a surface of an edge portion) of the anode foil 922. The insulating material 940 is made of a resin such as polyethylene, polypropylene or polyolefin.
According to the conventional electrolyte capacitor 900, the insulating material 940 is disposed between the bottom surface portion 912 and the capacitor element 920 and hence, it is possible to provide an electrolyte capacitor which ensures insulating property between the housing 910 and the capacitor element 920.
Further, according to the conventional electrolyte capacitor 900, the insulating material 940 is disposed between the bottom surface portion 912 and the capacitor element 920 and hence, a size of a gap formed between the bottom surface portion 912 and the capacitor element 920 becomes small thus providing an electrolyte capacitor having high vibration resistance.
Further, according to the conventional electrolyte capacitor 900, an electrolyte solution is filled in between the anode foil 922 and the cathode foil 924 and hence, even when a defect occurs in an oxide film on an edge surface of the anode foil where the defect is liable to occur in the oxide film, moisture contained in an electrolyte solution can repair a defective portion of the oxide film. As a result, it is possible to provide an electrolyte capacitor having a high withstand voltage and a small leakage current.